Airplane aileron



March 2, 1943- J. G. HAZARD ETAL 2,312,545

AIRPLANE AILERON Filed June 6, 1941 2 Sheets-Sheet 1 March 2, 1943.

J. G. HAZARD EI'AL AIRPLANE AILERON Filed June 6, 1941 2 Sheets-Sheet 2Patented Mar. 2, 1943 AIRPLANE AILERON John G. Hazard and Albert E.Arslan, Los Angeles, Calif., assignors to Vultee Aircraft, Inc., VulteeField, Calif., a corporation of Delaware VApplication June 6, 1941,Serial No. 396,816

6 Claims.

The present invention relates generally to airplane ailerons. Moreparticularly the invention relates to that type of airplane aileronwhich extends longitudinally of, and is hinged to, the trailing edge ofthe wing of the airplane and is statically and dynamically balancedabout the hinge line or axis.

In a conventional or standard aileron the hinge line is generallylocated behind the leading edge a distance approximately equal toone-fifth the distance between the leading and trailing edges of theaileron, i. e., a distance corresponding to approximately 20% of thecord of the aileron and it is customary to provide a longitudinallyextending primary load carrying beam which is disposed rearwards of thehinge line or axis. It is also customary to employ nose ribs on theforward face of the beam and tail ribs on the aft side or face in orderto establish the desired contour. The nose ribs are covered by a formedmetallic skin, and a trailing edge piece is employed to connect the aftends of the tail ribs. The structure comprising the primary loadcarrying beam, the nose ribs, tail ribs, formed metallic skin andtrailing edge piece is covered by doped fabric. In order statically anddynamically to balance the aileron about the hinge line ballast piecesof lead or like material are employed and these are placed within theformed metallic skin around the nose ribs. An aileron of theaforementioned type is objectionable from the standpoint of maintenancebecause of the fragility of the doped fabric covering. If a metallicskin is employed as the main covering instead`of a covering of dopedfabric in order to eliminate fragility and provide a more sturdyconstruction or design the weight of the aileron as a whole isessentially increased and it is necessary to employ a great amount ofballast for the purpose of maintaining proper balance of the aileronabout its hinge line.

The principal object of the invention is to provide an airplane aileronwhich is an improvement upon and has certain advantages over a standardor conventional aileron having either a doped fabric covering or acovering in the form of a metallic skin; by reason of the fact that itincludes a metallic skin but is so designed and constructed that it hasthe proper balance about its hinge line without the use of anyappreciable amount of ballast in its nose part. The improved aileron hasthe lightness of a fabric covered aileron while at the same time itpossesses the same sturdiness and rigidity as the heavier conventionalaileron with a metallic skin covering. In general the improved aileronis characterized by the fact that the longitudinally extending main loadcarrying beam is located in front of the hinge line or axis forbalancing purposes and is shaped to form a nose former.

Another object of the invention is to provide a statically anddynamically balanced airplane aileron of the type under considerationwhich not only is light and durable but also comprises or embodies fewerparts than standard or conventional ailerons.

A further object of the invention is to provide an airplane aileron inwhich the ribs are of onepiece design.

A still further object of the invention is to provide a statically anddynamically balanced airplane aileron of the type under considerationwhich includes simple and novel intercostals for reenforcing and crossconnecting certain of the ribs and supporting hinge plates.

Other objects of the invention and the various advantages andcharacteristics of the present aileron will be apparent from aconsideration of the following detailed description.

The invention consists in the several novel features which arehereinafter set forth and are more particularly defined by claims at theconclusion hereof.

In the drawings which accompany and form a part of this specification ordisclosure and in which like numerals of reference denote correspondingparts throughout the several views:

Figure 1 is a perspective view of an airplane Wing having an aileronembodying the invention;

Figure 2 is an enlarged fragmentary perspective view of the aileron,illustrating in detail the construction and design of the main orprimary load carrying beam and the one-piece cross ribs;

Figure 3 is a vertical transverse section through the central portion ofthe aileron showing the manner in which the upper and lower metallicskin sections are riveted in place and illustrating in detail theconstruction of the central hinge between the aileron and the wing;

Figure 4 is a fragmentary front View of the central portion of theaileron;

Figure 5 is a horizontal section on the line 5-5 of Figure 3; and

Figure 6 is a perspective view of one of the intercostals.

The aileron which is shown in the drawings constitutes the preferredform or embodiment of the invention. It is illustrated in connectionwith one of the side wings W of an airplane A andzserves in conjunctionwith a complemental aileron (not shown) onl the other side of theairplane as a medium for enabling the pilot to roll the airplane A onits longitudinal axis 'I'he wing W extends outwards from one side of thefuselage of the airplane A and is of conventional design orlconstruction. It tapers outwards both verticallyand horizontally andhas a cutout or recess in its trailing edge for the aileron.

'I'he aileron is hinged, as hereinafter described,

to swing upwards and downwards about a substantially horizontal hingeline and is essentially of unitary design. It is of all metalconstruction and as its primary or principal parts comprises alongitudinally extending primary load carrying beam 1, a series oflaterally spaced ribs 8, 3, I Il, II, I2, I3, I4, I5, I3, I1, I8, I3, 20and 2| an upper, metallic skin section 22 and a lowenmetallic skinsection 23. As shownin Figure 1, the aileron tapers outwards bothvertically and horizontally and its trailing edge is aligned with 'thetrailing edge of the 'wing W when the aileron is in its normal position.The beam 1 not only serves as the main or primary load carrying elementof the aileron lbut also as a nose former. It is dis.

posed in front of the hinge line, as hereinafter described, and operatestogether with an extremely small amount of ballast statically anddynamically to balance the aileron about the hinge line. 'The upperportion of the beam is curved or bent rearwards and embodies along itslongitudinal edge a full length integral depending flange 24. The lowerportion of the beam 1 is rearwardly curved, as shown in Figures 2 and 3,and has along its longitudinal edge a full length upstanding integralflange 25. The beam is preferably of one-piece design and is formed ofany suitable metal. It extends from one end ofthe aileron to the otherand has smooth inner and outer faces. The two flanges 24 and 25 serve asreenforcing means for the beam and are disposed in parallel relation.'I'he ballastis in the form of small pieces 1" of lead or like materialand these are located between the ribs and are connected by screws tothe front inner face of" the front portion of the beam.

The ribs are each of one-piece design and are formed of any suitablemetal. They are semipear shaped, as shown in Figures 1 and 3, and havesubstantially continuous integral right angle flanges 26 around theirmargins. The front portions of the ribs are curved conformable to, andabut directly against, the inner face of the primary load carryingbeam 1. Rivets 21 extend through the beam and the front portion of theflanges 26 and serve rigidly to connect the beam to the ribs. The upperforward portions of the ribs have notches 23. 'I'he depending flange v24of 'the beam fits within these notches, as shownjin Figures 2 and 3. Forthe purpose of connecting the flange 24 to the ribs angle bar type clips29 are provided. These clips correspond in number to and are associatedrespectively with the ribs and consist of vertically extending rear legs30 and vertically extending front legs 3i. The rear legs f lt againstand are riveted to the portions` of theribs that define the notches 28and the other legs, i. e., the legs 3i, extend at right angles to thelegs 30 and abut against and are riveted to the flange 24. 'I'he upperrear portions of the ribs slope downwards and rearwards and the lowerportions of the ribs slope upwards and rearwards, as illustrated inFigures 2 and 3. 'Ihe front or forward lower portions of the ribs havenotches 32 for accommodating the upstanding flange at the bottom marginof the primary load carrying beam 1. Such flange is anchored v orconnected to the ribs by way of angle bar type clips '33. The latterconsist of rear legs 34 which fit against and are riveted tothe frontlower portions of the ribs, and laterally extending legs 35 which abutagainst, and are riveted to. the flange 25.

'I'he upper skin section 22 extends from one end of the aileron to theother and serves as a covering for the top or upper portion of theaileron. The central and rear portions of the upper skin section 22overlie the central and rear upper portions of the flanges l28 and areconnected by rivets 38 to such portions of the flanges. The

' front'portion of the upper skin section 22 is bent or curved downwardsin conformityl with the upper portion of the beam 1 and laps or abutsdirectly against, such portion of the beam. Certain of the rivets 21extend through the front portion oi the upper skin section 22 and thecontiguous upper portion of the beam 1 and serve to hold the frontportion of the skin 'in ilxed from one end of the aileron -to the other.

relation with the beam.. The front edge of the upper skin sectionterminates at a point slightly above the cord line of the aileron. Thelower skin section 23, like the upper section, extends It is formedofany suitable sheet metal and is substantially imperforate. The -centraland rear portions of the lower skin section underlie and abut directlyagainst the central and. rear lower portions of the rib flanges 26 andare secured to such portions of the anges by way of rivets 38. The frontportion of the lower skin section 23 extends around and is curvedconformably tothe lower portion of the primary load 'carryingY beam 1.It abuts directly against said lower portion of the beam and is flxedlyconnected to the latter by way of certain of the rivets 21. The frontedge of' thel lower section and the front edge of the upper section arein lapped relation. The rear or trailing margins of the upper and lowerskin sections project beyond therear ends of the ribs and are securedtogether in lapped relation by-rivets l40. The front portions of theflanges 23, that is, the portions in front of the notches 28 and 32, areinwardly offset a distance corresponding to the thickness of the primaryload carrying beam 1. Due to the offset the upper and lower portions ofthe outer face of the beam are coplanar with the adjacent outer faceportions of the flanges and the two skin sections are hence smooth andembody no step formation.

The ribs I4 and I5 are located in the central portion of the aileron, asshown in Figure. 1, and are positioned closer together than theadjoining ribs. They are so constructed that the marginal flangesthereof project or extend away from one another. An intercostal 4I inthe form of a metallic plate or stamping extends between and serves tocross connect the front ends of the ribs I4 and I5. It is located behindthe hinge line of the aileron and embodies a pair of forwardly extendingside -flanges 42, a forwardly extending top-flange 43 and a forwardlyextending bottom flange 44. The side flanges abut against the frontportions of the ribs I4 and I5 and are riveted or otherwise flxedlysecured in place. The top flange 43 underlies and abuts against thesuperjacent portion of the upper skin section 22 and is connected to thelatter by rivets 45. The

bottom flange 44 of the intercostal 4I abuts against the subjacentportion of the lower metallic skin section 23 andis connected to suchportion by way of rivets 46. A metallic angle bar 41. extends across andis connected to the top margin of the intercostal 4|. This angle barembodies a top rearwardly extending leg which isv riveted to thesuperjacent portion of the skin section 22. The bottom margin of theintercostal 4I is reenforced by an angle bar 48 and this, as

shown in Figure 3, extends across the rear face portion of the bottommargin of the intercostal and has a rearwardly extending leg or flangewhich abuts against and is riveted to the subjacent portion of the lowerskin section 23. The intercostal 4I serves not onlyxto cross connect theribs I4 and I5 but also to support a pair of vertically extending hingeplates 49, The latter are positioned in laterally spaced relation infront of the intercostal 4I and have right angle rear flanges 50 which tagainst and are bolted to the side portions of the intercostal. Alignedholes 5I are formed in the lower portions of the plates 49, as shown inFigure 3. The central portion of the aileron is hinged to the adjacentportion of the wing W by way of a hinge bracket 52. This bracket isfixed to the rear aft spar of the wing (see Figure 3) and has arearwardly and downwardly extending arm 53. This arm extends into thefront central portion of the aileron through a rectangular hole 54 inthe primary load -carrying bottom 1 and U-shaped cutouts 55 n the frontportions of the upper and lower skin sections 22 and 23. The lower endof the arm 53 of the hinge bracket 52 ts between the lower portions ofthe hinge plates 49 and is pivotally connected to such plates by way ofa pin 56 which extends through a hole in the lower end of the arm and ismounted in the holes 5I. The hinge plates 49 and the arm equipped hingebracket 52 constitute a hinge whereby the aileron is permitted to swingupwards and downwards. The pin 56 constituting the hinge line of theaileron is located behind the main or primary load carrying beam I andthe beam ls so proportioned as to weight that it serves statically anddynamically to balance the aileron about its hinge line.

The ribs 9 and l0 are located at the outer end of the aileron and arespaced apart the same distance as the ribs I4 and I5. They are crossconnected by way of an intercostal (not shown) and the latter is thesame in design as the intercostal 4I and carries a pair of hinge plateswhich, to'- gether with a hinge bracket (not shown), constitute a hingefor the outer end of the aileron.

The ribs I 9 and 20 are located adjacent the inner end of the aileronand are cross connected by way of an intercostal (not shown). Suchintercostal is the same in design and construction as the intercostal 4Iand carries a pair of laterally spaced hinge plates (not shown) whichare like the hinge plates 49 and together with an arm equipped bracketon the trailing portion of the wing constitute a hinge for the inner endof the aileron.

The aileron is shifted or .controlled by way of a push and pull rod 51.The latter extends transversely through the outer rear portion of thewing W and has its rear end pivotally connected to the aileron by way ofa pair of pivot plates 58. The latter are welded to, and projectforwardly from, a curved plate 59. Such plate, as shown in Figure 2, islocated at one side of the beam opening 54 and is bolted to the frontportion of the upper skin section 22.

The herein described aileron, due to its construction and design, isboth light in Weight and durable. It is essentially statically anddynamically balanced by reason of the arrangement and design of theprimary load carrying beam I and requires but a minimum amount ofadditional ballast for purposes of properly balancing it about the hingeline. The beam has a threefold purpose in that it constitutes the mainload carrying element of the aileron, serves as a nose former and inaddition assists in statically and dynamically balancing the aileron. Byreason of the fact that the ribs are of one-piece design the aileron asa whole has but a limited or small number of parts and hence may beproduced at a low and reasonable cost. The aileron is characterized bythe fact that it is sturdy and rigid and is much lighter in weight thana standard or conventional aileron having either a doped fabric skin ora metallic skin.

Whereas the invention has been described in connection with an aileronit is to be understood that it is capable of being embodied in any typeof airfoil, such, for example, as an airplane elevator or rudder. It isalso to be understood that the invention is not to be restricted to thedetails set forth since they may be modified within the scope of theappended claims without departing from the spirit and scope of theinvention.

Having thus described the invention what we claim as new and desire tosecure by Letters Patent is:

1. An airfoil comprising a longitudinal beam extending from one end ofthe airfoil to the other curved transversely and forwardly so that it isof U-shaped cross section and serves as a nose former and designed andproportioned to form the main or primary load carrying member of theairfoil, a plurality of laterally spaced unitary rearwardly tapered ribsdisposed behind the beam and having convex U-shaped nose portions curvedconformably to and fitting within and secured to said beam, and acovering over the ribs.

2. An airfoil comprising a longitudinal substantially full length beamcurved transversely and forwards so that it is of U-shaped cross sectionand serves as a nose former and designed and proportioned to form themain or primary load carrying member of the airfoil, a series oflaterally spaced marginally anged rearwardly tapered one piece ribsextending rearwardly from, and connected to, the beam, a skin sectionserving to cover one side of the airfoil and having its central and rearportions tting against and secured to the adjacent portion of the ribflanges and its front portions extending around and secured to a portionof the beam, and a complemental skin section serving to cover the otherside of the airfoil and having its central and rear portions fittingagainst and secured to the adjacent portions of the rib flanges and thefront portion thereof fitting around and secured to the remainingportion of the beam.

3. An airfoil comprising a longitudinally extending full length metallicbeam curved transversely and forwards so that it is of U-shaped crosssection and serves as a nose former, and designed and proportioned toform the main or primary load carrying member of the airfoil, a seriesof laterally spaced marginally flanged onepiece rearwardly tapered ribsdisposed behind the beam and having convex U-shaped nose portionsthereof shaped conformably to, and tting within and secured to, thebeam, a skin section serving to cover one side of the airfoil and havingthe. central and rear portions thereof fitting against and secured tothe adjacent-portions of the rib flanges and its front portion curvedaround and secured to a portion oi' the beam, and a complemental skinsection arranged to cover the other side of the airfoil and having thecentral and rear portions thereof fitting against and secured to theadjacent portions of the rib flanges and its front portion curved aroundand secured to the remaining portion of the beam.

4. An airfoil comprising a longitudinally extending substantially fulllength beam curved transversely and forwards so that it is of U- shapedcross section and serves as a nose former, designed and proportioned toform the main or primary load carrying member of the airfoil, and havingintegral inturned flanges along its lon'- gitudinal margins, a series ofone-piece laterally spaced ribs disposed behind the beam and havingconvex U-shaped nose portions thereof shaped conformably to, and fittingwithin an-d secured to the beam, and provided with marginal notches foraccommodating the beam flanges, angle type clips extending between andconnected to the notch defining portions of the ribs and the adjacentportions of the flanges, and a covering over ribs.

5. A movable airfoil having hinge means in theI front portion thereofwhereby it is supported for swinging movement about a longitudinallyextending hinge line, and comprising a longitudinally extendingsubstantially full length beam `positioned in front of the hinge line,curved transversely and forwards so that it is of U-shaped cross sectionand serves as a nose former, and designed and proportioned to form themain or primary load carrying member of the airfoil and also to assistin statically and dynamically balancing the airfoil about said hingeline, a plurality of laterally spaced unitary rearwardly tapered crossribs disposed behind the beam and having convex U-shaped nose portionscurved conformably to, and fitting within and secured to, said beam, anda covering around the beam and ribs.

6. Amovable airfoil comprising a longitudinally extending substantiallyfull length beam curved transversely and forwards so that it is of U-shaped cross section and serves as a nose former and designed andproportioned to form the main or primary load carrying member of theairfoil, a plurality of laterally spaced unitary ribs disposed behindthe beam and having U-shaped nose portions curved conformably to, andfitting within and secured to, said beam, an intercostal positionedbehind the beam and between two of the ribs and having a hinge plate onthe front face thereof, and a covering or skin over the ribs, said beamhaving an opening therein in front of the hinge plate for accommodatinga hinge arm.

r JOHN G. HAZARD.

ALBERT E. ARSLAN.

